Vandetanib in patients with previously treated RET-rearranged advanced non-small-cell lung cancer (LURET): an open-label, multicentre phase 2 trial.

BACKGROUND: RET rearrangements are rare oncogenic alterations in non-small-cell lung cancer (NSCLC). Vandetanib is a multitargeted tyrosine kinase inhibitor exhibiting RET kinase activity. We aimed to assess the efficacy and safety of vandetanib in patients with advanced RET-rearranged NSCLC.

METHODS: In this open-label, multicentre, phase 2 trial (LURET), patients with advanced RET-rearranged NSCLC continuously received 300 mg of oral vandetanib daily. RET-positive patients were screened using a nationwide genomic screening network of about 200 participating institutions. Primary endpoint was the independently assessed objective response in eligible patients. This study is registered with UMIN-CTR, number UMIN000010095.

FINDINGS: Between Feb 7, 2013, and March 19, 2015, 1536 patients with EGFR mutation-negative NSCLC were screened, of whom 34 were RET-positive (2%) and 19 were enrolled. Among 17 eligible patients included in primary analysis, nine (53% [95% CI 28-77]) achieved an objective response, which met the primary endpoint. In the intention-to-treat population of all 19 patients treated with vandetanib, nine (47% [95% CI 24-71]) achieved an objective response. At the data cutoff, median progression-free survival was 4·7 months (95% CI 2·8-8·5). The most common grade 3 or 4 adverse events were hypertension (11 [58%]), diarrhoea (two [11%]), rash (three [16%]), dry skin (one [5%]), and QT prolongation (two [11%]).

INTERPRETATION: Vandetanib showed clinical antitumour activity and a manageable safety profile in patients with advanced RET-rearranged NSCLC. Our results define RET rearrangement as a new molecular subgroup of NSCLC suitable for targeted therapy.

FUNDING: The Ministry of Health, Labour and Welfare of Japan and the Practical Research for Innovation Cancer Control from the Japan Agency for Medical Research and Development, AMED.